For the third time this week, an NYPD officer has fatally shot and killed a suspect.

18-year-old Ramarley Graham was gunned down Thursday inside the bathroom of his Bronx home following a foot pursuit by a team of plainsclothes cops. He was unarmed.

Investigators say police spotted Graham--who's had 8 prior arrests on charges including robbery, marijuana possession and resisting arrest-- on White Plains Road when he started to run. Police chased Graham to his home at 749 East 229 Street. After a struggle, an officer fired one shot at close range from his 9mm semiautomatic handgun. The bullet hit Graham in the chest and he collapsed. It's unclear, according to The New York Times, if the gun was fired during the struggle or if the two were separated when the shooting took place. [UPDATE: The New York Post reports the two officers involved in the incident believed Graham was carrying a weapon. Commissioner Ray Kelly says the two officers have been placed on restrictive duty. The NYPD now believes Graham did not struggle with the cops. In the apartment, one of the officers reportedly screamed, "Show me your hands! Show me your hands!", followed by "Gun! Gun!" before firing the fatal shot.]

A small amount of marijuana was found in the toilet and police found no weapons in the house. According to The Daily News, officers had seen Graham moments before the shooting adjusting his waistband, and thought he had a gun.

Graham was pronounced dead at Montefiore Medical Center.

"Everybody's kids get into trouble," Graham's grieving mother, Constance Malcolm, told CBS. "He smoked a little weed, but you know, like all the little, young kids does. And that's what he had on him when they were chasing him."

She added, "In the bathroom they shot him. My 6-year-old son was there and saw everything," Malcolm said. "I'm going to get justice."

The teenager's neighbors struggled to comprehend the tragedy Thursday. From The Times:

Near a local deli on Thursday, Jessica Rodriguez, 34, said Mr. Graham had offered to pick up coffee for her every morning. "When I bring my kids to school, he's getting a peppermint tea," she said. "He played football in the backyard with my kids."

At the deli, a group of boys gathered, blasting a Jamaican song from a small set of speakers. The lyrics chronicled the death of a young man at the hands of the police, they said.

On January 26, an off-duty cop shot and killed a 22-year-old carjacking suspect. And on January 29th, another off-duty cop shot and killed a 17-year-old who was trying to mug him.